I have a 2001 S40 after about an hour drive at 60mph I stopped for 15 min, and left engine running, when I went to leave I noticed the idle going up and down by a couple hundred RPM. I was ready to put in reverse and engine went to about 3000 rpm all by it's self. I tried to kick it down but no luck. I then shut it off. No restart, it would turn over but almost like no spark and a strong gas smell (flooding). I had it towed the hour home and after unloading at home it started rough at first then smoothed out and idled ok. I shut off and restarted and OK except check engine light is now on and radiatior cooling fan would not shut off. I pulled the fuse and after a couple hours put in back in and fan stayed off. Any ideas as to what happened <_< I'm glad I didn't have it in gear when it took off. There is no chance that my foot was on the pedel.